That would be extremely cool. But is a dedicated/specially designed chip necessary for such low-intensity computing?

I would think that you'd prove the market first in an FPGA with hard processor design first. Performance/battery life would not be as good, but it would be good enough for many products -- certainly good enough for the first gen.

can you imagine the feeling of empowerment felt when walking into these hallowed halls? (Cincinnati Public Library 1874 from Classic Pics):

Look at the elegant carvings and structure of the building and the infrastructure to get access to the books and so forth. Truly awesome.

Now, if most of each one of those books contained a record of someone buying a latte or losing a satoshi-dice bet then we have a pretty good representation of Bitcoin. A really good example of taking something worthwhile and sullying it.

if you fail to see the fundamental difference between those stacks and the already primitive flash drive on my newish machine, i fail to see the interest hanging out here has for you.

There's also the issue that what the blockchain records is not records of transactions, but rather proofs of ledger integrity.

The blockchain is a statement that, "no matter how many lattes were purchased or Satoshi Dice bets were placed, the number of bitcoins available for spending has been perfectly, is and always has been, exactly correct"

Recording all transactions that have happened is done because that's the easiest way to generate the proof, not because storing that kind of history is the purpose of Bitcoin.

...Recording all transactions that have happened is done because that's the easiest way to generate the proof, not because storing that kind of history is the purpose of Bitcoin.

Well said.

Bitcoin is the first monetary system to credibly offer perfect information to all economic participants.Cryptoasset rankings and metrics for investors: https://onchainfx.comFrontpage of crypto: https://messari.io

...Recording all transactions that have happened is done because that's the easiest way to generate the proof, not because storing that kind of history is the purpose of Bitcoin.

Well said.

embedding the hash of UTXO in the block headers and retaining only the last few hundred blocks is being experimented with as a client option.

The real trick will be figuring out a secure way of letting the entire network do it.

I don't think committed UTXO sets by themselves are sufficient.

I hadn't thought about this...

If a wrong UTXO hash would invalidate the block it should work, no? But then there's also incentive to omit it due to the risk of the block being rejected. Requiring it would be a hard fork? Is that the problem?

If the protocol was changed to require a valid UTXO set hash for a block to be considered valid, and if enough entities kept enough history to catch any cheating before its too late it should probably work.